A light-emitting device, such as an LED or the like, has a higher power consumption characteristic and is smaller than a fluorescent lamp, an incandescent lamp, or the like, and thus, it has been used in various types of applications. In particular, the LED has recently taken center stage as a flash light source in a digital camera installed in a mobile electronic device.
To efficiently use an LED in a camera, light is not simply irradiated but is efficiently irradiated according to a viewing angle of the camera. A lens is used to efficiently irradiate light and may be designed in consideration of a beam angle, uniformity, luminous flux efficiency, etc. that are required. The lens converts a luminous flux of the LED for functions as described above, and thus, is referred to as a luminous flux converting lens.